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# Write balanced equations for the following reactions: (i) Iron (II) chloride solution with sodium hydroxide solution. (ii) Chlorine and cold dilute sodium hydroxide solution. (iii) Zinc and sodium hydroxide solution. (iv) Sulphur dioxide and sodium hydroxide solution. (Give the equation for the formation of the normal salt).

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## (i) Iron (II) chloride (pale green colour) solution reacts with sodium hydroxide solution to form dirty green precipitate of ferrous hydroxide, which on further addition of excess sodium hydroxide stays insoluble. ${\mathrm{FeCl}}_{2}+2\mathrm{NaOH}\stackrel{}{\to }\mathrm{Fe}\left(\mathrm{OH}{\right)}_{2}+2\mathrm{NaCl}\phantom{\rule{0ex}{0ex}}\mathrm{Iron}\left(\mathrm{II}\right)\mathrm{chloride}\mathrm{Iron}\left(\mathrm{II}\right)\mathrm{hydroxide}\phantom{\rule{0ex}{0ex}}\left(\mathrm{pale}\mathrm{green}\right)\left(\mathrm{dirty}\mathrm{green}\mathrm{ppt}\right)$ (ii) When chlorine gas is passed through cold dilute sodium hydroxide solution, sodium hypochlorite (NaOCl, bleaching agent) is formed. ${\mathrm{Cl}}_{2}\left(\mathrm{g}\right)+2\mathrm{NaOH}\left(\mathrm{aq}\right)\stackrel{}{\to }\mathrm{NaCl}+\mathrm{NaOCl}+{\mathrm{H}}_{2}\mathrm{O}\phantom{\rule{0ex}{0ex}}\mathrm{Chlorine}\mathrm{Sodium}\mathrm{Sodium}\phantom{\rule{0ex}{0ex}}\mathrm{hydroxide}\left(\mathrm{cold}\right)\mathrm{hypochlorite}$ (iii) Zinc reacts with hot and concentrated sodium hydroxide solution to form colourless, soluble sodium zincate salt with the release of hydrogen gas. $\mathrm{Zn}+2\mathrm{NaOH}\stackrel{}{\to }{\mathrm{Na}}_{2}{\mathrm{ZnO}}_{2}+{\mathrm{H}}_{2}\phantom{\rule{0ex}{0ex}}\mathrm{Zinc}\mathrm{Sodium}\mathrm{hydroxide}\mathrm{Sodium}\mathrm{Zincate}\mathrm{Hydrogen}\mathrm{gas}\phantom{\rule{0ex}{0ex}}\left(\mathrm{colourless},\mathrm{soluble}\right)$ (iv) Sulphur dioxide reacts with sodium hydroxide solution to form sodium sulphite and water. ${\mathrm{SO}}_{2}+2\mathrm{NaOH}\stackrel{}{\to }{\mathrm{Na}}_{2}{\mathrm{SO}}_{3}+{\mathrm{H}}_{2}\mathrm{O}\phantom{\rule{0ex}{0ex}}\mathrm{Sulphur}\mathrm{dioxide}\mathrm{Sodium}\mathrm{sulphite}\phantom{\rule{0ex}{0ex}}\left(\mathrm{White}\mathrm{ppt}.\right)$  Suggest Corrections  0      Similar questions  Explore more